Improvement in adjustable dental brackets



H. A. HALL.

ADJUSTABLE DENTAL-BRACKET.

".PEERS, FHOTO-LITHOGRAPHER. WIBMINGTON. D4 c.

UNITED' STATES Prrrnlvr @Priono HORACE A.VHALL, OF TROY, NEW YORK.

IMPROVEMENT IN ADJUSTABLE DENTAL BRACKETS.

Specication forming part of Letters Patent No. 173,623, dated February 15, 1876; application tiled June 1, 1875.

pact in form, readily adjusted, and securely held, for the purpose set forth. In the drawing, Figure 1 represents a elevation of my device, with the extensionarm atv positions indicated by Figs. 1, 2, 3,

and a reversed or swinging position is shown at point 4. Fig. 2 represents a plan of the same, showing a view ofthe table support. Fig. 3 is a transverse section, showing the friction bearing-joints of the arms` to the same. r

My device is cast or constructed of metal of any desired quality or finish, and with such proportions as to size -and form as may suit the manufacturer.

The hinged or pivoted support B swings in A position -from right to left, or vice versa, be-

tween bearings, which are firmly attached to the wall or vertical surface of the room.

I also construct the swivel or pointed arms A of such length as will give the desired range 0f an arc upward and downward and I have found that such a range as will give a vertical chord of an arc from twenty-four to thirty inches, will best subserve the requisite conditions for effective Work in dental operations, Whenever the seat of the patient is required to be lowered or elevated.

The arms A maybe of any desired shape, although a curvilinear form afords a more graceful appearance.

The pivoted support B has a shoulder extending therefrom, (seen in Fig. 1,) with two arms having Vtubular ends, through which screw-rods (seen in Fig. 3) are passed, and held by thumb-screws G, having right and left hand screw-threads for increasing friction.

means of the screw-thread and thumbscrew C any necessary friction may be produced, so as to hold up the bearing-arms and extension-arms and table at any required height automatically, as one hand placed upon the table'may depress or elevate it to any desired rest.

A horizontal sleeve, S, with tubular crosssections thereto, alfords the means of uniting the outer extremities of the swiveljointed arms A in a similar manner ,to that of the inner extremities of the same.

The distance of the table-support H from the operator is increased or diminished by means of the lateral movements of the tubular sliding arm S', and the telescopic extensionarm E.

rlhe sleeve S being fully extended and the extension-arm E fully drawn out, in the first position, marked 1, Fig. 1, and partially extended in the other views, a rigid position of the arm E is caused by screwing down the clamp D at the outer end of the tubular arm S', while the arm S is held by thethumbscrew'F, although both extension-arms will work effectively, if left free to be moved laterally. y

The table-support H may be rmly fastened on the extremity ofthe arm E, or revolve around a central pivot in the usual manner.

In adjustable dental brackets heretofore used, or inthe operation of movable brackets which may have been deemed sufficient by the inventor for table-supports, there is much inconvenience in actual use, or a lack of the necessary friction on the bearing surfaces or joints, which ditliculties I think l have overcome in my movable bracket.

All the changes of the location of the table with my device may be made with one hand, and by means of the friction bearing-joints the table and`bracket-connections are held at the desired rest and position automatically, andat the same time the extension-table is vuniformly'held in its horizontal position, at

any required height, to hold thc tools, as S', and telescopic extension-table-supporting adapted to the work, or the raising or lowerrod E. constructed substantially as and for ing of the dent-a1 chair in manipulations in the purpose set forth.

the month of the patient. HORACE A. HALL. I claim- Witnesses: v The combination of the double parallel A. J. WEISE,

friction lbearing-arms A, sliding tubular arms J W. PALMER. 

